I need some advice - I am going to batch leach some milled ore samples and plan on using AC to capture the values. Instead of stripping the AC I was wondering if it can be smelted, maybe with a bit of litharge as a collector and some borax to slag off contaminants. I understand the carbon can be “ashed” in an electric muffle furnace at 650 celsius for 6-8 hours (I don’t have a muffle furnace) and thinking a gas furnace or torch (which I do have) might create too much wind and either volatilize the microscopic gold particles and/or blow the particles and ash out of the pan - hence the smelting question. I’m talking about a handful of AC per batch.

Trail riding & Bedrock Busting for Gold
Take a trip with Jeff and Mike as they go on a trail ride up in the Sierra's to look for some Gold trapped in Bedrock .
https://www.youtube.com/watch?v=TNI4hF0yOMk

It's almost summer, though it still doesn't feel like it. I prepared well for spring run off by removing snow from all around the shaft area, tons and tons of snow and all by hand. It was good to get my body ready for mucking pay. I've had reasonable success thawing gravel with my heat rods and I'm getting more efficient with the drilling apparatus. But just when things were clicking along, my generator died on me mid way in a thaw. I tried repairing it but had no immediate success so I decided to have another try at getting my 8K Lister running. I've had the Lister for over a year and never been able to get it started. So I removed the injectors and tubes, checked for good fuel pressure, tightened all connections, adjusted valve lash and made as sure as I could all the air was removed from the system and gave it a crank. It fired up. Yessss. And I had good voltage off the generator. Now the job was to get it down to the shaft. I strung a log chain between two trees on either side of the generator, raised it off the ground with a come along and dropped it into my Otter sled which I then pulled down the hill to the shaft with the wheeler. Since there were no trees there to work with I rigged up a tripod tall enough to do the same hoist procedure out of the sled. The final 20 feet were accomplished with a chain saw winch. I fabbed an outlet junction box from an old generator, mounted it in the hoist shack and ran a power cord from the Lister to the box. All was in place for power down in the shaft. Couldn't get it started again. I had replaced all the filters and found the main fuel filter had a second gasket that was not supposed to be there, so I took that out. Air must have been getting through at that point. Also I discovered the former owner had incorrectly plumbed the water separator. I re bled the system and hooked up a brand new battery. It started and ran just like it came from the factory. Praise God. I now had power. I could get down to the bottom of the shaft and see what headaches were awaiting me from the rain and melting shaft ice that had accumulated over the two weeks I was without power.. It was a mess, but I got my deep well pump running and removed what water had not yet frozen (a considerable amount). Loose ice was shoveled into the hoisting bucket and the remainder I busted up with the jack hammer and hoisted it out. A number of tools were coated with ice and had to be knocked clean and or thawed out up top. Now I can get back to the incomplete thaw I began three or four weeks ago; the rods are still in place. It will take an additional 20 hours to complete, but at least I'm back in business.

The old timers did dig there but not to much depth. Maybe 4 or 5 feet. Little "pickers" in their tailings. 4 or 5 grains.
I'm thinking they did not go deep enough.
Where they did put their adit was in a strange location.... not related to the intersection and no signs of gold in their tailings. They were in bluestone and the area of the intersection has some igneous material.

I found one a while back that was maybe 300 feet long down the side of a hill and it was surprisingly straight down the hill. Your line of gold may be a pocket in the quartz vein that has eroded out and freed to roll down the hill. Knowing that there is a vein, I'd detect and dig in the vein where your line crosses the vein.

Chris.... all the quartz was found in a straight line running straight down a 52 % slope for a distance of 500 feet and about 10 feet wide(further than I thought).
I will add that at top upper end of this "line" is a gold bearing quartz vein that runs perpendicular. But, I can't imagine something bleeding downhill that far without spreading out. It is a very uniform slope. no swales to keep it together.

I would say that the "hardpan" is like a hard compressed clay. Can be broken up with a pick. I suspect that it may be several feet to hard bedrock(probably a "bluestone?") Maybe I'll do a little picking.
Thanks.

Likely there is something there, but you have given me so little to go on its real hard to say. If it were me I would dig around above the spot where the upper most piece was found. I dont know exactly what you mean by hard pan - caliche? Hard clay? hard bedrock? If its possible to dig through the "hard pan" I would do so.
The upper most piece could be 2 feet below the location of the pocket or 20 feet below it or something in between. Its also possible that all the pocket has spilled out and no more of the quartz in place remains.
The density of gold bearing quartz is much less overall than the density of solid gold. So the quartz specimens tend not to sink so far into the soil. They also give a weaker response than solid gold, so you may not be detecting them as deeply.

I discovered a piece of quartz with gold while detecting. Further detecting revealed pieces of quartz with gold every 10 or 15 feet for a distance of maybe 300-400 feet. One containing an ounce of gold.
All were found in a straight line and not more than maybe 4 to 6 inches deep. This line was running straight downhill.
In digging down to try to uncover a vein of quartz, I find a hard pan layer down about a foot. Not the hardrock I was looking for. No signs of quartz.
Why are all these pieces more or less lying at the surface? Does gold ever form like this or is there a vein down there somewhere.?

Hey Flint, thanks for that. By the way, I love your stuff (frozen tundra tunneling / drifting)... wish I was half as tough as you my friend!
Gravel pump - I wonder most about a dredging application to transfer a mixed size aggregate slurry, sharp or rounded rock, cobble, sand, broken bedrock etc.. could be for river dredging or for a pit bottom recovery application, to sweep off the bedrock after the excavator. The examples of pumping head ore I posted all appear to be of comparitively small size aggregate ores, sand and clay - some appear to use a screen (grizzly) at the intake nozzle so as not to pass larger rock. I haven't come across a working example of moving mixed size and larger aggregate but I wrote to Mark Keene about a video I saw on Youtube (see link below) and he said the 6" gravel pump would pass a 5.5” sphere, didn't mention if that was a continuous duty task but I assume the design is for river dredging (?)…I think it was a prototype but he said the’ve used these pumps for years. Gold dredgers on the Amazon use 12” gravel pumps mounted on huge barges, but again, it seems mostly for silt and sandy ores.
I inquired about some inexpensive gravel pumps in South America (made in Brazil) and the manufacturer made a recommendation for 10 sets of wear parts (side plates and impellers) as well as an extra case or two - so that tells you something about the expected wear! (hence the rubber lined US built pumps).
The advantage of a gravel pump is the ability to transfer a slurry straight up in the air and out over a distance to a recovery plant, but like you say needs big horse power…but also notice the engine / pump doesn’t need to be located near the intake…the Keene design claims 100’-150’ of lift using a pony pump and a jet to maintain prime for the 6” gravel pump coupled to a 100 hp diesel engine.
Is it just me or is this not a very cool way to move head ore to a recovery plant. It's potentially a substantial cost savings in heavy equipment, maybe no need for a trommel because you could use a vibrating screen deck instead, the pump having a macerator effect to help bust up and dissolve clays.
Maybe I should start another post titled “mining with a gravel pump" and see if it gets more attention than this one. I would love to learn more and what applications have proven to be practical.
From Mark Keen:
Jeff
We do not carry the pumps shown in the links below. We use a Wemco model CE pump. We have used these for mining for over 50 years and have had very good performance reliability. The thing that we like is the 4” pump can pass up to a 3.5 sphere and the 6” pump can pass up to 5.5” sphere.
Just the pump alone sell for just under 10K
6" gravel pump. http://www.youtube.com/watch?v=rb1KdeU1Ju4
http://www.youtube.com/watch?v=kBwCiFQbDpo

I worked for an operation that used a very large rubber lined pump to suck the gravel coming off a 250 yd per hour trommel The 1/2"- slurry was pushed about 75' through an 8" pipe then up 10' on to a monster jig. It took a 100hp motor to run the pump but it sure did the job. I'm sure you could go smaller but you're still going to have to have some pretty heavy horse power.

When the excavator cannot scrape or dig into harder bedrock, what are other practical methods to recover the gold laying on top of and wedged into the bedrock? I suppose by suction using a gravel pump but have not actually seen this in use. Venturi suction like what is used on a typical suction dredge won’t work in a deep hole. A gravel pump however will transport the slurry vertically and out a distance to a wash plant. They make gravel pumps as small as 4”, popular in Brazil. Gold miners in South America use 8” 10” 12” gravel pumps as a primary feed method to a rustic sluice, mostly for head ore that makes a sandy / clay slurry, pumping from excavated pits. It’s impressive actually, very practical and definitely a cheap way to move ore to a recovery plant! In some cases the ground water supply from natural filtration maintains a certain water level in the pit along with some makeup water from another source. They also use high pressure pumps to hydraulic excavate and move material in the pit.
Does anyone have experience with gravel pumps?
Here’s some youtube links of the South Americans (note that environmental impact is of little concern!)

Gary - I think there is some miscommunication here. I have no idea what you are asking, and I am kind of thinking you are not very clear on it either. Chlorite is a mineral which does not contain precious metals. Chlorides are a group of minerals, but the only ones you might see in an ore are silver chlorides, the mineral name of which is Chlorargyrite. See: https://en.wikipedia.org/wiki/Chlorargyrite
Other precious metals do not form mineral chlorides because they are water soluble.
I know of no process which extracts precious metals using silver nitrate.
Pulverizing to more than 350 mesh is a mistake, and will cause lower recover of metals rather than more. You should not crush that fine.
So the whole thing is pretty muddled and maybe you could start fresh and tell us in detail what you have and what are wanting to do,

Not an awful lot to report. I'm about 9' in my drift which is about 5' wide and 5' 6" high at the top of an arch. My gravel is very atypical with large lenses of pure muck in between a jumble of chunky, fine and ground up shist bedrock, large cobbles, angular and rounded quartz and a smattering of intrusives. There's no bedding or layering except for the muck and I even have bones almost to bed rock, one of those being a young mammoth jaw complete with two teeth found 2' off bed rock. It's quite a conundrum. And the gold is not primarily just off bed rock but spotty and scattered throughout the entire column. Got any ideas? Heavy flood event?? I'm also continually making changes to my heat rods for the gravel thawing. My latest iteration should be ready to test out in about 2 weeks. From calculations and prior experience I'm expecting some really effective thawing. I'm also improving my drilling system making it faster and less labor intensive. My bucket hoist has been working nearly flawlessly. I'm ready for the cold to leave though I'm not looking forward to fighting with runoff again this year. Got some ideas how to mitigate it. More soon. Thannks all for your continued interest.